Polyfluoroureas

ABSTRACT

HYDROXYMETHYLATED DERIVATES OF POLYFLUOROALKYLUREAS ARE USEFUL FOR IMPARTING OIL, WATER AND CREASE RESISTANCE TO FIBROUS SUBSTRATES. THE POLYFLUOROALKYLUREAS HAVE THE FORMULA:   RF-Y-N(-R1)-CO-N(-R2)-R   WHEREIN RF IS N-PERFLUOROALKYL GROUPPF4-6 CARBON ATOMS; Y IS AN ALKYLENE BRIDGE OPTICALLY INTERUPTED WITH --O--, --S--, --SO--, --SO2--, --SO2NR&#39;&#39;--, --CONR&#39;&#39;--, ==C(O)0--, AND --NR&#39;&#39;-- WHEREIN R7 REPRESENTS HYDROGEN,LOWER ALKYL AND -UREIDO; R1 AND R2 ARE EACH HYDROGEN, LOWER ALKYL OR TAKEN TOGETHER CAN COMPLETE AN IMIDOZLIDONE OR PYRIMIDONE RING AND R IS HYDROGEN, LOWER ALKYL, OR RF--Y--, IT BEING PROVIDED THAT AT LEAST ONE UREA NITROGEN ATOM HAS HYDROGEN BONDED THERETO AND IT BEING FURTHER PROVIDED THAT THE NUMBER OF CARBON ATOMS IN Y IS 2-12 FOR THE NON-INTERRUPTED BRIDGE AND 2-60 FOR THE INTERRUPTED BRIDGE.

United States Patent 3,838,165 POLYFLUOROUREAS Walter Blochl, Karlsruhe,Germany, assignor to FMC Corporation, New York, N .Y.

No Drawing. Continuation-impart of abandoned application Ser. No.830,849, June 5, 1969. This application July 10, 1972, Ser. No. 270,208

Int. Cl. C07d 49/30 US. Cl. 260-3095 3 Claims ABSTRACT OF THE DISCLOSUREHydroxymethylated derivatives of polyfluoroalkylureas are useful forimparting oil, water and crease resistance to fibrous substrates. Thepolyfluoroalkylureas have the formula:

wherein R is n-perfiuoroalkyl group of 4-16 carbon atoms; Y is analkylene bridge optionally interrupted with -O, S, SO-, --SO SO NR',-OONR, C(O)O, and N-R'- wherein R represents hydrogen, lower alkyl andureido; R and R are each hydrogen, lower alkyl or taken together cancomplete an imidozolidone or pyrimidone ring and R is hydrogen, loweralkyl, or R,--Y-, it being provided that at least one urea nitrogen atomhas hydrogen bonded thereto and it being further provided that thenumber of carbon atoms in Y is 2-l2 for the non-interrupted bridge and2-60 for the interrupted bridge.

This application is a continuation-in-part of Ser. No. 830,849, filedJune 5, 1969, and now abandoned.

This invention pertains to the treatment of porous substrates,particularly fibrous materials. The invention is especially concernedwith rendering textiles oil, water and crease resistant by treating themwith certain hydroxymethylated polyfluoroalkylureas.

The treatment of porous substrates such as leather, Wood, textiles andthe like for the purpose of modifying their properties, is well known.In the textile field, for instance, it has long been the practice toapply wax or resinous coating on cloth in order to increase its waterrepellency. Later, emulsion polymers were developed which not onlyimparted water repellency to textiles but also improved their oil andstain repellency. The drawback of such materials is that they areeventually removed from the cloth after a few dry cleanings and/orlaunderings.

Also known are materials capable of actually reacting with the textilesubstrate, the co-called fiber reactive compounds, and these proved tobe highly resistant to removal by ordinary cleaning procedures. A classof fiber reactive compounds which has attracted considerable interestare the hydroxymethylated ureas. When applied to textile materialsfollowed by heat curing in situ, such urea derivatives impart excellentwrinkle resistance to the fabric substrate. However, thehydroxymethylated ureas thus far reported do not significantly increaseand in some instances may even decrease the soil and oil repellency oftextiles.

Manifestly, there is a need for a class of hydroxymethylated ureascapable of imparting both crease resistance and oil and soil repellencyto textile materials.

It has now been discovered that the above recited properties arepossessed to a remarkable extent by the hydroxymethylated or etherifiedderivatives of certain polyfluoroureas, the formula of which is whereinR, is n-perfluoroalkyl group of 4-16 carbon atoms; Y is an alkylenebridge optionally interrupted with -O--, S, SO--, -S0 SO N-R, CONR, C(O)O, and NR wherein R represents hydrogen, lower alkyl and ureido; R and Rare each hydrogen, lower alkyl or taken together can complete anirnidozolidone or pyrimidone ring and R is hydrogen, lower alkyl, or RY-, it being provided that at least one urea nitrogen atom has hydrogenbonded thereto and it being further provided that the number of carbonatoms in Y is 212 for the non-interrupted bridge and 2-60 for theinterrupted bridge.

The polyfluoroalkyl ureas of the invention can be prepared using theknown methods of synthesizing substituted ureas. In general, therequisite polyfluoroalkylamine,

is reacted with a carbonyl derivative X-fl-X' wherein X and X arehalogens or amino groups. lllustrative carbonyl derivatives areExemplary reactions are depicted in the following schematic equations:

Rr-Y-N-IH oil-c i-nnm Rr-Y-IF-C-NRR: base-H01 Reaction 1) isconveniently performed by heating stoichiometric amounts of thereactants until evolution of ammonia has ceased. Temperatures in theneighborhood of 150 C. are usually sufiicient. Reactions (2), (3) and(4) tend to be somewhat exothermic and normally require some externalcooling to prevent their becoming too vigorous. The use of inertsolvents such as saturated or aromatic hydrocarbons are also effectivein moderating the reactions. Once the initial exothermic reaction hassubsided, it may require heating to elfect its completion.

Suitable bases are the usual type of acid acceptors such as teritaryorganic bases, e.g. pyridine, trimethylamine, triethylamine, etc., themineral bases, e.g. alkali metal carbonates, e.g. sodium or potassiumcarbonate and the like.

Where Y in the formula is a non-interrupted alkylene bridge, therequisite polyfiuoroalkylamine is obtained by reacting a polyfluoroalkyliodide R (CH I where n is 1-12 with ammonia or a monofunctional primaryor secondary amine having the desired substituents. The reaction iscarried out in the known manner of alkylating amines. Typically,stoichiometric amounts of an amine having at least one amino hydrogenand the desired fluorinated iodide, R (CH I are heated at mildlyelevated temperatures, usually in the presence of an inert solvent. Theresulting polyfiuoroalkylamine is isolated by distillation orcrystallization or by other procedures known to the art.

Where Y in the formula is a hetero interrupted bridge, the requisitepolyfluoroalkylamines can be realized using any number of preparativeprocedures. For instance, where the hetero atom is oxygen or acombination of oxygen and nitrogen, a polyfiuoroalkanol,

R (CH OH is condensed with ethyleneimine as follows:

RKCHQHOH mCHa CH3 where m is a whole number of 1 to 4. Or thepolyfluoroalkanol can first be reacted with ethylene oxide and then withethylene imine. By replacing the polyfiuoroalkanol with the analogousthiol, there is obtained the corresponding sulfur interrupted alkylenebridge. Moreover, the S can be oxidized to produce a sulfoxide, SO, orsulfone, -SO linkage.

Polyfluoroalkanols and thiols are known compounds which are disclosed inthe literature.

As previously pointed out, the fiuorinated ureas herein are converted totheir methylolated derivative prior to being applied to the fabricsubstrate. The reaction is generally carried out in a known manner ofmethylolating urea derivatives under alkaline conditions, using aqueousformaldehyde. In a typical procedure, 1.5 to 4 moles of formaldehyde inthe form of a 37% aqueous solution is reacted with 1 mole of the ureacompound at a pH of about 7-9 by heating-the components for about 2hours. Sodium hydroxide solution is used to adjust the pH. After thereaction is completed, neutralization to pH 7 results in a stablesolution containing the hydroxymethylated polyfluoroalkylureaimpregnating agent. The reaction mixture can be diluted to the desiredstrength for impregnating fibrous substrates without isolating andpurifying the product.

Where the polyfluoroalkylureas are applied to the fabric from an organicsolvent, it may be desirable to employ them in the form of their loweralkoxy methylated derivatives, which can be obtained by etherificationof the methylol group with the lower alkanols such .as methyl, ethyl,n-propyl, isopropyl, n-butyl, isobutyl alcohol or similar loweralkanols. Accordingly, it is to be understood herein that when speakingof methylolated derivatives of the polyfluoroalkylureas of subjectinvention, such derivatives include alkoxy methylated derivatives.

In accordance with the invention, the polyfiuoroalkylurea is applied totextiles and similar fibrous substrates from aqueous solution bypadding, spraying, dipping or the like. Preferably the concentration ofthe fiuorinated urea is from about 0.2 to about 3.0%, althoughconcentrations in the range of 0.1 to 5% are also satisfactory. Zincnitrate, magnesium chloride, ammonium chloride, zirconium oxychloride,basic zirconium acetate, zirconium acetylacetonate complexes,

or other catalysts commonly employed to cure methylolated ureas ontextile substrates, are useful for ouring the fiuorinated ureas. Thetreated substrates are dried at C. for several minutes and cured byheating several minutes at to 180 C. A convenient curing procedureconsists in heating the treated fabric from about 1 to 5 minutes at C.to 160 C. The impregnating bath may contain supplementary componentssuch as flame retardants, non-fluorinated ureas for addedcrease-proofing, hand modifiers, lubricants, etc.

I have found it especially advantageous to incorporate zirconiumcompounds in the impregnating baths containing the fluorinated ureas ofthe invention. Thus, the use of zirconium compounds in concentrations ofabout 0.1% to about 3.0% applied to the textiles before, during or afterthe treatment increases the durability to laundering to a marked degree.Zirconium oxychloride, basic zirconium acetate, ammonium carbonatezirconate and zirconium chelates formed from triethanolamine, ammoniumlactate or acetylacetonate are especially suitable in this connection.To a certain degree, titanium chelates can be used in lieu of thezirconium derivatives, although the latter are preferred.

Texiles impregnated in accordance with the invention have 3M oilrepellency values of between 90 and 120. If compounds with 8 to 14carbon atoms in the perfluoroalkyl radical are selected, an oilrepellency value of 120 is obtained with 0.2% to 1% active material onthe fabric. This value drops to no more than 100 to 110 after washing 5times with a detergent in a household washing machine. The values ofzirconized fabrics drop the least. The decrease after 5 dry cleaningsamounts to only about 10 to 20 points.

In applying the compounds of the invention to textiles, samples of 80" x80" cotton cloth are soaked in an aqueous isopropanol solution of thehydroxymethylated or etherified polyfluoroalkylurea containing magnesiumchloride as curing agent. The pH of the solution is adjusted to 6 withhydrochloric acid. After soaking a few minutes, the cloth is removedfrom the bath, air dried and cured at about C.

The invention is illustrated by the following nonlimiting examples:

EXAMPLE 1 The amine, n-C F CH CH NHC H -n (n 1.3384), prepared fromn-butylamine and n-C F CH CH I, is dissolved in a mixture of pyridineand anhydrous ether. The,

mixture is cooled in an ice bath and gradually added to a cold solutionof carbamoyl chloride in ether. The mixture is stirred and allowed towarm up and then refluxed for about an hour and cooled. After filtrationthe urea is isolated by removal of the solvent.

Methylolation of A mixture of the urea in aqueous isopropanol is treatedwith 37% aqueous formaldehyde solution. The pH is adjusted to about 8with aqueous sodium hydroxide. The mixture is heated several hours tocomplete the reaction.

EXAMPLE 2 n-cgF 7CH2CH2SCH2CH2NHCONH3 To a solution of sodium ethoxide,made from 0.75 g.

Y of sodium and 60 ml. of absolute ethanol, is added 14.4

g. of H-CgF CHzCHzSH in m1. of absolute ethanol. To this is added asolution of 3.7 g. p-chloroethylamine in absolute ethanol, prepared fromthe hydrochloride and alcoholic potassium hydroxide. The reaction isstirred and heated at 45 C. under nitrogen for several hours and thenallowed to stand at room temperature overnight. From the reactionmixture is isolated 10.5 g. of

m.p. 40-42" C. t

The amine H'CgFmCHzCHzSCHzCHzNHz and an excess of urea are heatedtogether at 115 to 130 C. The product is washed with water and extractedwith chloroform. Removal of the solvent affords solid n-C F CH CH SCH CHNHCONH Methylolation of A mixture of the aforesaid urea in aqueousisopropanol is treated with 37% aqueous formaldehyde solution. The pH isadjusted to about 8 with aqueous sodium hydroxide. The mixture is heatedseveral hours to complete the reaction.

EXAMPLE 3 A mixture of 86 g. of n-C F CH CH l, 13.7 g. of thiourea and150 ml. of 95% ethyl alcohol is stirred and refluxed for nine hours. Thesolvent is removed affording 98 g. of isothiouronium salt. The salt isdissolved in a mixture of 800 ml. each of warm acetic acid and water andthen cooled to 10 C. Chlorine is bubbled into the mixture for one hourat 10 C. The mixture is stirred for one additional hour and the productII-CgFmCHgCHzSOzCl collected by filtration, m.p. 62-64 C.

To a mixture of 0.05 mole of aforesaid in tetrahydrofuran is added 0.1mole of ethylene diamine. The mixture is stirred and warmed to completethe reaction. The mixture is filtered and the solvent removed to givethe crystalline amine,

pyridine and ether is cooled in an ice bath. To the mixture is addeddropwise an ether solution of carbamoyl chloride with stirring. Afterthe addition the reaction mixture is stirred and allowed to warm up toroom temperature. The mixture is refluxed for a few minutes. Afterremoval 6 of the pyridine hydrochloride by filtration and the solvent bystripping, the crude urea,

is isolated in satisfactory yield.

Methylolation of An aqueous isopropyl alcohol solution of the urea isreacted with aqueous 37% formaldehyde solution. The pH is adjusted toabout 8 and the mixture is heated several hours.

EXAMPLE 4 1-(B-Aminoethyl)-2-imidazolidone is added to a well stirredmixture of n-C F CH CH SO Cl, finely powdered and anhydrous potassiumcarbonate in anhydrous tetrahydrofuran. The mixture is refluxed forseveral hours to complete the reaction. The inorganic materials areremoved by filtration and the imidazolidone isolated by removal ofsolvent.

Methylolation of Methylolation is carried out as usual in aqueousisopropyl alcohol solution at a pH of about 8 using aqueous formaldehydesolution.

EXAMPLE 5 A mixture of g. of n-perfluorooctyl iodide and 20 g. ofallylurea is heated to 90 C. with stirring. Azobis(isobutyronitrile)(0.2 g.) is added and the reaction becomes exothermic. After 1% hoursthe reaction is complete. The solid product is finely divided and washedwith 1,1,2-trichlorotrifluoroethane. Seventy-four grams of the urea isobtained, m.p. C.

A mixture of 47 g. of

H-CaFuCHzCHICHgNHCONHz,

5 g. of 5% Pd/C (palladium/charcoal catalyst), 5.9 g. of powdered,anhydrous potassium carbonate and 200 ml. of absolute alcohol ishydrogenated in a Paar shaker overnight. After removal of the catalystand inorganic materials, the alcohol is evaporated. The solids arewashed with dilute sodium hydroxide and water and then dried to obtain24.4 g. of the desired urea, m.p. 134 C.

Methylolation of l1-C F17CH2CH2CH2NHCONHg A mixture of the urea inaqueous isopropanol is treated with 37% aqueous formaldehyde solution.The pH is adjusted to about 8 with aqueous sodium hydroxide. The mixtureis heated several hours to complete the reaction.

EXAMPLE 6 n-CgF ncHgcHaN O O HNCHIBHB The diamine,Il-CgFmCHgCHzNHCHzCHgNHz ("D25 1.3438), 0.1 mole, prepared fromCaFmCHzCHzI and excess ethylenediamine, is dissolved in anhydrous ethercontaining 0.21 mole of pyridine. The mixture is cooled in an ice bathand stirred. Phosgene is slowly added until approximately ten grams havebeen added. The mixture is stirred one hour further and then allowed towarm up to room temperature. After refluxing for 1% hours, the mixtureis filtered to remove the pyridine hydrochloride. The ether solution iswashed with sodium bicarbonate solution and water. After drying andremoval of the solvent, the imidazolidone is obtained as a crystallineproduct in good yield.

7 Methylolation of A mixture of the imidazolidone in aqueous isopropanolis treated with 37% aqueous formaldehyde solution. The pH is adjusted toabout 8 with aqueous sodium hydroxide. The mixture is heated severalhours to complete the reaction.

EXAMPLE 7 n-cgF qcHgcHgN A solution of 0.04 mole of the diarm'ne,

IICgF CHgCHzNHCHgCHgNHz,

in 25 ml. of benzene is added slowly with cooling to a solution of 1.96g. (0.01 mole) of silicon tetraisocyanate in 60 ml. of benzene. Afterthe addition the mixutre is reflnxed for 45 minutes. The benzene isremoved under vacuum and is replaced by 60 ml. of isopropyl alcohol andml. of water. The mixture is refluxed for about 30-40 minutes andfiltered hot to remove the gelatinous silica. The silica is washed withhot acetone several times. The desired diurea is obtained in good yieldfrom the filtrate by precipitation with addition of water.

Methylolation of n-C F CH CH NwONH )CH CH NHCONH A mixture of the diureaaforesaid in aqueous isopropanol is treated with excess 37% aqueousformaldehyde solution. The pH is adjusted to about 8 with aqueous sodiumhydroxide. The mixture is heated several hours to complete the reaction.

What is claimed is:

1. A polyfiuoroalkylurea of the formula:

2. A polyfiuoroalkylurea according to claim 1 and having the formula 3.A polyfluoroalkylurea according to claim 1 and having the formulaReferences Cited UNITED STATES PATENTS 3,398,182 8/1968 Guenthner 260455NATALIE TROUSOF, Primary Examiner M. A. M. CROWDER, Assistant ExaminerUS. Cl. X.R.

